Visibility of color symbology in head-up and head-mounted displays in daylight environments

摘要

Color-coded symbology has the potential to enhance the performance of people using head-up and head-mounted displays, as well as head-worn, optical see-through, augmented-reality displays. The distinguishing feature of these displays is the optical combiner that presents symbology overlaid upon the forward natural scene. The presence of high-ambient daylight can desaturate the symbol colors, making them difficult to identify. This is especially true for blue symbols that become faint and colorless in even moderate daylight. We defined a set of colors for testing based on color coding conventions, color symbology research, and results from our previous testing. Included in this set was blue-prime, a color that lies between blue and cyan. We then conducted an experiment to test the visibility of color symbols, the naming of symbol colors, and the legibility of color text mixed with daylight. Results were statistically analyzed and modeled using color-difference formulae. Additional experiments were conducted to test the effects of increasing the luminance of blue symbols and shifting primary colors to increase the luminance. Specific attention was given to the symbol color blue, where the alternative color blue-prime was shown to always outperform the color blue while retaining the color name blue.